Apparatus for treatment of nerves and muscles by means of electric impulses



y 1945- P. MORLAND ET AL 7 APPARATUS FOR TREATMENT OF NERVES AND MUSCLES BY MEANS OF ELECTRIC IMPULSES Filed Sept. 5, 1941 4 3 Sheets-Sheet 1 Fig. 7.

i r II {*0 39 E I 'g lllm m a 2 as May 8, 1945. P. MORLAND ET AL 2,375,575

APPARATUS FOR TREATMENT OF NERVE-S AND MUSCLES BY MEANS OF ELECTRIC IMPULSE-S Filed Sept. 3, 1941 s Sheets-Sheet 2 Fig. 6. H9. 7 I Hg. 8.

Fig.9.

y 1945. P. MORLAND ET AL 2,375,575

APPARATUS FOR TREATMENT OF NERVES AND MUSCLES BY MEANS OF ELECTRIC IMPULSES Filed Sept. 5; 1941 5 Sheets-Sheet 3 Hg. 71 Fig. [2. Fig. 73.

' spoken, the inertia voltage is constant.

Patented May 8,1945

APPARATUS FOR TREATMENT OF NERVES AND MUSCLES BY MEANS OF ELECTRIC IMPULSES Preben Morland, Gen

Application September 3, 1941, Serial No. 409,385

tofte, and Jorgen Adolph Smith, Copenhagen, Denmark; vested in the Alien Property Custodian In Denmark June 22, 1940 2 Claims.

The invention relates to an apparatus fo treatment of nervesand muscles with electric impulses, for instance for therapeutic and diagnostic purposes.

In such apparatuses it is known to use electric impulses the voltage curve of which is monopolar or dipolar. The dipolar'curve whichconsists of a portion situated on one side of the voltage of repose and, a corresponding part that is situated on the other side of this voltage is the most frequently used curve, and may relatively simply be produced in a form in which the duration of the impulse, especially the duration of the first part of the impulse, which is of the greatest importance tothe treatment, is very short. In the known apparatuses it is usual that the individual impulses are emitted automatically in succession, with a mutual time interval that is greater than the duration, of each individual impulse. It is also known to arrange the apparatuses in such a manner that the time interval between the impulses and the amplitude of the same is varied periodically and automatically, at a relatively slow'rhythm.

The present invention relates to an improvement in apparatuses of the said nature, whether the same are arranged for a monopolar or a muscle to react. It is, however, not necessary to use a rectangular impulse. Even if the impulse is rounded at the top, and its width decreases upward, it can be used in the measuring. We

have thus a simple means for performin the said measurements.

The above mentioned known apparatuses for treatment of nerves and muscles with electric impulses are not suited for performing the measurements referred to here. It is certainly feasible by these apparatuses to alter the amplitude of the impulses and, consequently, the area of the impulses, but ,this is done by a short constant duration of the impulses-for which reason it is impossible to attain sufl'lciently large areas, without the maximum value of the voltage becoming too high. This drawback of the apparatuses, however, may be removed according to the invention, if the apparatuses are arranged in dipolar curve shape, for the emission of individual impulses or a series of such, or for constant time interval and amplitude, or for a periodical variation of one or the other, or both, of these features. I

The invention is based on certain observations concerning'jthe behavior of muscles actuated by an electric current; and, more particularly, the

time whichelapses from the-beginning of an electric treatment to the reaction of the muscle,

at-a certain electric voltage which according to the investigator Lapicque is assumed to be twice the voltage (the rheobase) that is .just sufficient to produce a reaction in the muscle. Roughly f reaction varies with the acting voltage in such a manner that the-product A during the measuring, the measure for the state ofthinuscle, inrespect to the inertia of reaction, will be equal to the area of a-rectangular voltage impulse that is just able to cause the above.

of the voltage and the inertia of reaction at this I For this reason it'is not such a manner that the area of the impulse curve may be altered by varying the duration of the impulses.

In this manner we attain not only an apparatus for diagnostic use, but the apparatus'may also be used in the electric nerve and muscle therapeutics; Experience has shown, for ininstance, that diseased muscles will only react when the impulsecurve has a relatively large area. In the treatment of such muscles it is preferable to start the treatment with impulse curves with this area and, gradually as the treatment proceeds, to reduce the area. A reaction will then constantly be attained, at decreasing areas, until finally the area is attained, or passed beyond,that a healthy nerve would transmit to the muscle concerned. v

In the'use of the apparatus for training of muscles, the same is. adjusted for emitting series of impulses, the amplitude and time interval of the impulses being either maintained constant or caused to vary periodically, as mentioned Monopolar as well as dipolar impulses may be used. In the case of the latter, the last part of the impulses, the polarity .of which is opposite that of the first part, will sometimes not come into operation. In certain muscles and for certain arrangements of the current-supplying electrodes, the two parts of the impulses may be caused toact on various parts of the muscle, in

such'a manner that both impulse parts become v and the nature of 'the treatment, to be able to make further changes in the shape of the impulse cu'rves, means are further provided for removal of certain .parts of thevoltage curve of the impulses, in such a manner that in each indi- .vidual case the form of impulse may be attained a discharging valve, for instance a glow lamp,

the ignition voltage of which is higher than its extinction voltage, and by discharging or charging the capacity by way of a discharging valve. In such an apparatus, the capacity according to the invention is rendered variable or adjustable,-

in order to alter the duration of the impulses. For the same purpose, the circuit of the dischargmay beconnected to a special winding on an outlet transformer which is providedin the apparatus, and from the secondary winding of which the impulses altered by the arrangement according to the invention are taken,

The invention is further explained in the following, with reference to the drawings, in which Fig. 1 shows a wiring diagram for a construction of the portion of the apparatus according to ing valve may contain a variable or adjustable I inductance or resistance or both.

The apparatus may further be constructed in such amanner that the impulses are amplified by an amplifier valve by which a periodically varying modification of the amplitude of the impulses may also be produced. In such a construction of the apparatus, the latter is fitted according to the invention with means for altering of a gridbia's on the amplifier valve, in order to compensate the amplitude variation contingent on a modification of the duration of the impulses. The apparatus may further befitted with means .for altering a grid bias on the discharging valve byway of which the capacity is discharged or charged, in order to compensate the variation in the impulse interval contingent on the change in the duration of the impulses. According to the invention it is preferable to provide a common adjusting member for the means by which the grid bias on the amplifier valve or the discharging valve, or both, is altered, and for the adjustable or variable capacity or inductance or both, it being frequently desired to use the apparatus in such a manner that the area of the impulse curve is altered, without the simultaneous alteration of the impulse amplitude and the time interval between the impulses.

The means for removing certain parts of the impulse curve comprise preferably a rectifier arranged for complete or partial removal of the impulse voltages'that exceed a certain constant or rhythmically pulsating positive voltage. The

said means may further comprise a rectifier constructed for complete or partial removal of the impulse voltages that are lower than a certain constant or rhythmically pulsating negative voltage. 1 4

One, or both, of the said rectifiers have preferablymeans for adjustment of the rectifier efi'ect to values between complete rectification and the the invention in which the impulses are generated, and which contains means for varying their duration and time interval.

Figs. 2, 3 and 4 show various forms of voltage curves produced by various adjustments of the part of the apparatus that is shown in Fig. 1.

Fig. 5 is a diagram of a construction of the part of the apparatus according to the invention that makes it feasible to remove certain parts of the voltage curve.

Figs. 6, 7, 8 and 9 show examples of voltage curves for one single impulse, gradually as the latter passes through the part of the apparatus shown in Fig. 5.

Fig. 10 shows an apparatus for controlling the device shown in Fig. 5, and

Figs. 11, 12 and 13show various manners of connection for thearrangement shown in Fig. 5.

The apparatus shown in Fig. 1 consists of one part for the generation of impulses and for the control of their mutual time interval, and one part for control of the amplitude of the im- Dulses.

Across the primary winding I l of a transformer l2, a glow lamp I0 is connected to the positive terminal l3 of a source of voltage and, across an adjustable condenser H, to the negative terminal ii of the source of voltage. A pentode valve I6 is disposed as a variable shunt over the condenser H, the plates of the condenser being connected to the cathode l1 and the anode l8 in the valve. ,The .controlling grid I3 01' the valve is connected to a terminal 20 by way of which a rhythmically pulsating voltage may be supplied, if desired. The shielding grid 2| of the valve receives a suitable positive voltage in that it is connected to a point between a fixed resistance 22 and a variable resistance 23 inserted in series, between the terminals l3 and IS. The shielding grid 2| is further coupled to the oathode I? by way of a condenser 24. The intercepting grid 25 of the valve is connected to the oathode I 1. The resistance in the valve l6 may be adjusted to various values by an adjustment of the sliding contact 26 of the resistance 23.

The secondary winding 21 of the transformer I2 is connected to a variable resistance 28 by means of which it is feasible to adjustthe value of the inductance produced by the transformer l2, in the circuit of the glow lamp I0.

In the construction described, the condenser I4 will alternately be charged by way of the glow lamp I 0 and discharged by way of the pentode valve I6. The varying voltage thus produced on the condenser i4 is directedacross an adjustable condenser 29 to the controlling grid 30 of an amplifier valve in the form of a pentode valve 3|. In other respects this valve is connected in a similar manner as the valve IS, with the exception that its anode circuit contains an, inductance 32 which is variable, in that it is shunted with an adjustable resistance 33. The shielding-grid resistance is determined by adjustment of a. sliding contact 34.

The outlet voltage of the apparatus is delivered byway of the terminals 35 and 36, the former one of which is connected to the anode of the valve 3| by way of acondenser 31, while the latter is con-. nected to the cathode of the said valve.

If the inductance produced by the transformer I2 in the circuit of the valve I is small, short impulses of the shape shown in Fig. 2will occur at the terminals 35 and 36, the duration t of the impulses being dependent on the said inductance and the capacity of the condenser I4. The time interval T between the-impulses depends on the resistance in the valve I6, and the amplitude of the impulses depends on the amplification produced in the valve 3|.. The time interval may consequently be adjusted by an adjustment of the sliding contact 25, and the amplitude by adjustment of the sliding contact 34.

If an impulse curve is desired with a greater duration t", as shown in Fig. 3, this result may be attained by. increasing the. inductance produced by the transformer I2, or by increasing the capacity of the condenser I4. At the same time a change will be effected in the time interval and the amplitude of the impulses. The time interval may be reduced to its former value by an adjustment of the sliding contact 26. The impulse amplitude may be reduced to its former value by an adjustment of the sliding contact ,34, or of the resistance 33, or of both of these members simultaneously. The maintenance of a constant time.

use .of special valves, also concave voltage curves may be attained.

If the apparatus is to operate with periodic variation of the time interval between the impulses and of the impulse amplitude, this result may be attained by supplying a rhythmically pulsating voltage to the terminal that is connected to the controlling grid I9 in the valve I6 and to a I terminal 38 connected to the controlling grid in the valve 3|. I

The apparatus described may be altered in various manners, without the scope of the invention being transgressed. The discharging valve will thus not necessarily have to be a, glow lamp, but

may be a so-called gas triode. The condenser I4,

instead of entering in series with the discharging valve, may be placed in parallel withthe same,

- .in such a manner that the condenser is not charged but discharged by way of the lamp. Fur

ther, inductances 39 and of various magnitude may be inserted in connection with the transformer I2, or instead ofthe same, as shown in Fig. 1, the said inductances being inserted singly by means 'of a throw-over switch' 4|. Theseare merely a few examples out ofa large number of possiblemodifications.

It should be'.noted that an adjustment of the condenser 29 will also afiect the duration of the and I0, respectively, to two conductors I05 and I06, respectively, the other ends of which are connected to outlet terminals I01 and I03, respectively. As far as direct current is concerned, the condensers I03 and I04 serve to separate the device from the apparatus to which the inlet terminals IOI and I02 are connected, and in which the impulses are produced. The latter may have the shape shown in Fig. 6. Theimpulse is dipolar, and consists of a positive part I09 and a negative part 0. Between the conductors I05 and I06, a rectifier is inserted which consists of a rectifier valve III, the anode II2 of which is connected to the conductor I05 by way of a variable resistance II3 and a condenser Ill, and the cathode I I5 of which is connected to the conductor I06 by way of two condensers H16 and II! disposed in series. The condenser H6 is shunted with a portion of a potentiometer I I8, the binding posts of the said condenser being connected, respectively, to one end of the potentiometer H8 and a sliding contact I I9 on the same. The effect of the rectifier is, as follows:

The potentiometer H8 is assumed to be conneoted to a source of voltage in such a manner that the free end of the potentiometer H8 has a positive potential, relatively to the other end of the same. The sliding contact II9 has consequently a potential that is situated between the values of the potentials impressed on the ends of the potentiometer H0. The condenser H6 is charged from the potentiometer to a voltage that is determined by the position of the sliding contact II9. Between the conductors I05 and I03 there is normally no. potential difference, but

whenever an impulse passes the conductor I05 the following happens:

At low. positive voltage I values, the anode I I 2will not yet be positive, relatively to the cathode II5, audit will therefore repel the electrons emitted from the latter. At the moment when the impulse voltage has been raised to such a value that the potential of the anode II2 becomes zero, relatively to the cathode II5, the rectification will commence. This rectiflcation is not complete, i. e. it depends on the resistance that is inserted in the circuit, i. e. mainly on the magnitude of the resistance II3.

If the latter is gradually reduced, the rectiflcation will be more and more perfect. After the impulse running along the conductor I05 has passed the parallel connection formed by the of the curve;

impulses, in such a manner that this condenser maybe used as a means of adjustment, either alone or in combination with the adjusting means inserted in the circuit of the discharging lamp.

In the construction shown in Fig. 5, the impulses are supplied by way of two inlet terminals.

- MI and I02 connected, by way of condensers- I03 rectifier, it will have the shape shown in Fig. 7. The curve drawn with full lines corresponds to the variable resistance II3 being cut off entirely, while the finely drawncurve parts I20 and I 2| correspond to a portion of the said resistance being inserted, in such a manner that only a partial rectification is'efiected. The horizontal line I22 limiting the curve in the direction upward corresponds to a complete rectification above the limit concerned. At any voltage lower than the one determined by the line I22, the anode H2 is negative, relatively to the cathode II5, and the rectifier has therefore no influence on the shape Between, the conductors I05 and W6, another rectifier is inserted which .has for its: object to cut oif the top of the negativeportion IIO ofthe impulse. This rectifier isarranged in the same The reference numerals for the individual parts-of the rectifier are fitted with index marks but correspond otherwise to the numerals used inthe rectiiler described above. The only difference between the two rectifiers consists in thatthey are disposed with opposite polarities, relatively to the conductors I05 and I06.

The rectifier containing the rectifier-valve II5' has the same effect on the negative part of the impulse running along the conductor I05, as has the rectifier containing the rectifier valve I I5, as described above, on the positive part of the same impulse. When the impulse running along the conductor I05 has moved .past the parallel connection formed by the rectifier containing the rectifier valve 5', it will have the shape shown in Fig. 8, provided that the resistance 3' has been cut out, which corresponds to a complete rectification below the limit concerned. The lower part of the negative portion of the impulse curve is cut off along the straight line I, and the position of the said line is determined by the position of the'sliding contact II9 on the potentiometer 8' which is connected to a source of voltage. The variable resistance 3' has such a magnitude that the rectifier has no effect on the shape of the impulse curve, when the resistance is inserted with its full size. The same applies to the resistance "'3 and the rectifier belonging thereto.

Finally, a rectifier is inserted between the conductors I05 and I06, which consists of a double rectifier valve I32 with two anodes I33 and I34 and two cathodes I35 and I36 which are both connected to a sliding contact I3I on a potentiometer I36 inserted between the conductors I05 and I06. The anodes I33 and I34 are connected each to'one end of the potentiometer I38.

When the sliding contact I31 is at the end of cause a rectification of the negative part of an impulse running along the conductor I05. the anode I34 being in that case positive, relatively to the cathodes I35 and I36. In the last mentioned case, the impulse running along the conductor I05 has the shape shown in Fig. 9. The impulse I23 shown here is rectangulan-pr mainly rectangular, and monopolar. By means of the slidin contact I 31, the rectifying effect on the two'impulse parts may be adjusted. The potentiometer I38 is of such a size that it does not act as any appreciable loading for the impulse voltages occurring on its binding posts. 7 last described rectifier the symmetry of'the\ two parts of the impulse curve may be improved, or

the positive or the negative part-of the impulse curve-may be removed completely.

Impulses with the desired curve shape may be delivered at the outlet terminals I01 and I06. The invention is not limited to the shape of impulses shown in Fig. 6, although this is the form of impulses that is mainly used. I

The impulses are generally emitted automatically in succession with a mutual time interval Bymeans of this eflectecl, instead of by placing a constant on-age on the potentiometers I IBand I I8, by impressing on the same a voltage varying in the same manner as the time interval between the individual impulses and/or the amplitude of the same. In this manner a series of impulses on the terminals I01 and I08 will be attained, the curve shapes of the same being similar and depending on the position of the sliding contacts H9 and 9'.

In the arrangement shown in Fig. 5, three rec- 'tifiers with special couplings are used, but the on the drawing.

Fig. 10 shows an apparatus intended to replace the elements of Fig. 5 shown in the dotted box II 8a for producing the controlling voltages impressed, as mentioned above, on the potentiometers H8 and H8, when the time intervals and amplitude of the impulses vary automatically. The apparatus contains a pentode valve I40 with an anode I, an intercepting grid I42, a shielding grid I43, a controlling grid I44 and a cathode I45. The anode I4I receives a positivevoltage by way .of a resistance I46 connected to a binding post I4'I which in its turn is connected to the positive terminal of a source of voltage, the negative terminal of which is connected to a binding post I48. The intercepting grid I42 is connected to the cathode I45. The shielding grid I43 receives a positive voltage across a-resistance I49, and is coupled to the binding post I48 by way of a condenser I50. Between the shielding grid I43 and the binding post I48, a. resistance I5I is further inserted. Across four potentiometers, the cathode v I is connected to the binding post I48. Twov of these potentiometers are the potentiometers H8 and I I0 shown in Fig. 5 with sliding contacts I I9 and 3', respectively. The other potentiometers I28 and I52 having the sliding contacts I29 and I53, respectively, may be used, provided that the arrangement shown in Fig. 5 contains still two rectifier circuits to be controlled in the above mentionedmanner. The potentiometers H0 and 8', I20 and I52 are shunted with a condenser I54. The grid I44 receives a voltage varying in the same manner as the time interval and amplitude of the impulses. Between the anode MI and the-binding post I48, a variable resistance I55 is disposed, which is adjusted in such a manner that connection for the arrangement shown in Fig. 5.

Fig. 11 showsan outlet transformer in the apparatus for producing the electric impulses. The

primary winding of the transformer is marked.

I56. The impulses are delivered by way of a secondary winding I51. The device is connected to a special winding I50 on the transformer. The

winding I58 acts as a. short-circuit for the not desired parts of the impulse curve, while the that serves to generate the impulses, the latter being delivered by way of the secondary winding of the transformer.

- a great duration are used Fig. 12 shows a choking coil I59 inserted in the outlet circuit of the apparatus for generating the impulses. The inlet terminals l! and I02 for the device shown in Fig. 5 are connected each to one end of the choking coil I59.

Fig. 13 shows a resistance I60 inserted in the outlet circuitof the apparatus, by way of which resistance the device shown in Fig. 5 is connected. In the two latter cases, the desired impulses are delivered by way of the outlet terminals I01 and I08 of the device.

If the outlet circuit of theapparatus is resistance-coupled, as shown in Fig. 13, the device may be inserted at another point that is situated nearer to the inlet circuit for the amplifier situated in front thereof.

Instead of the potentiometers H8 and H8 in connection with the condensers H6 and I I6, respectively, batteries of suitablessizes may be inserted between the cathodes H5 and H5, respectively, and the condensers H1 and I l1, re-

- spectively.

are used for the production of what is called, in physiology, single contractions for diognostic purposes, or for treatment of muscles requiring an especially lenient treatment. Sections may also be used in sensitive measurements with the use of high frequency.

Having thus described our invention, what we claim is:

1. Apparatus for the treatment of nerves and muscles comprising means having a pair of output terminals for producing at said output terminals a succession of electric impulses having positive and negative cycles, the duration of said impulses being shorter than the time interval between two successive impulses, adjustable means for controlling the amplitude of said impulses and for varying the time interval between said individual impulses, means constituting a source of rhythmically pulsating potential to be impressed upon said last, named means, means for altering the area and shape of the impulse curve comprising a first rectifier connected to curve shapes and impulses the curve area of which is sections of given impulse curves.

, The pointed curve shape, the lower part of which may be cut off may be used for treatment of healthy muscles, in order to prevent the same from degenerating, in the case of the corresponding nerve or nerves'being temporarily or for a longer period set out of function. Sectional curves are used as measuring curves, but they may also be used in series and with adjustable time interval. The sectional curves may further be used for sensitive actuation for measurement of sensibility disturbances and for actuation of cordial muscles. Pointed curves and curves with for training of muscles, all depending on the physiological state of the same. Sections in the shape of single impulses said output terminals and adjustable to remove portions of the positive cycles of the impulse voltages greater than a. predetermined positive voltage, a second rectifier connected to said output terminals and adjustable to remove portions of the negative cycles of the impulse voltages greater than a predetermined negative voltage, a resistor having an adjustable tap and connected across said output terminals, and a full wave rectifier having two anodes connected to said output terminals respectively and cathodemeans connected to said adjustable tap.

2. Apparatus as claimed in claim 1, including an external source of voltage, means for adjustably connecting said external source in series with said first and second rectiflers across said output terminals, and means for periodically varying the magnitude of the voltage of said external source.

PREBE'N MORLAND. J ORGEN ADOLPH SMITH. 

